Electric and Magnetic Fields for the Proposed Microstrip Antenna with DGS for Breast Cancer Detection

This paper presents the design of microstrip antenna with defected ground structure (DGS) for the detection of breast tumor in microwave imaging system at operating frequency of 2.45GHz. Four types of microstrip patch antennas have been designed using microstrip feed inset with grounding patches at 2.45 GHz operating frequency using dielectric substrates, FR4 (ɛr = 4.4 F / m). The results are collected via the intensity of electric (E), magnetic fields (H) and current densities. The antenna is examined with a 3D breast model structure with specific dielectric value and conductivity. From the results, it shows that antenna with design structure, Design 4 produce a good intensities values of both E and H fields respectively with the presence of the tumour, and gives the value of 7083 V/m and 35.5 A/m while without the presence of tumour is 7186 V/m and 35.8 A/m compare to other proposed antennas

Spectral coding performance under free space optical medium

This paper focus on performance of code Zero Correlation-Correlation (ZCC) in free space optical communication. The ZCC code has a superior characteristic which eliminate the overlapping code between any users. Due to this high class characteristic, the code improves the performance of the conventional code in free space optical environment. In this paper the analysis performance of bit error rate is considering the avalanche (APD) noise, thermal noise and multiuser interference. The result shows that ZCC code improve the performance of conventional code in term of number of users, power received and data bit rate

The effects of unbleached and bleached nanocellulose on the thermal and flammability of polypropylene-reinforced kenaf core hybrid polymer bionanocomposites

The thermal, thermo-mechanical and flammability properties of kenaf core hybrid polymer nanocomposites reinforced with unbleached and bleached nanocrystalline cellulose (NCC) were studied. The studied chemical composition found that unbleached NCC (NCC-UB) had 90% more lignin content compared to bleached NCC (NCC-B). Nanocelluloses were incorporated within polypropy-lene (PP) as the matrix, together with kenaf core as a main reinforcement and maleic anhydride grafted polypropylene (MAPP) as a coupling agent via a melt mixing compounding process. The result showed that the thermal stability of the nanocomposites was generally affected by the presence of lignin in NCC-UB and sulfate group on the surface of NCC-B. The residual lignin in NCC-UB appeared to overcome the poor thermal stability of the composites that was caused by sulfation during the hydrolysis process. The lignin helped to promote the late degradation of the nanocom-posites, with the melting temperature occurring at a relatively higher temperature of 219.1? C for PP/NCC-UB, compared to 185.9? C for PP/NCC-B. Between the two types of nanocomposites, PP/NCC-B had notably lower thermo-mechanical properties, which can be attributed to the poor bonding and dispersion properties of the NCC-B in the nanocomposites blend. The PP/NCC-UB showed better thermal properties due to the effect of residual lignin, which acted as a compatibilizer between NCC-UB and polymer matrix, thus improved the bonding properties. The residual lignin in PP/NCC-UB helped to promote char formation and slowed down the burning process, thus increasing the flame resistance of the nanocomposites. Overall, the residual lignin on the surface of NCC-UB appeared to aid better stability on the thermal and flammability properties of the nanocomposites

The effects of unbleached and bleached nanocellulose on the thermal and flammability of plypropylene-reinforced kenaf core hybrid polymer bionanocomposites

The thermal, thermo-mechanical and flammability properties of kenaf core hybrid polymer nanocomposites reinforced with unbleached and bleached nanocrystalline cellulose (NCC) were studied. The studied chemical composition found that unbleached NCC (NCC-UB) had 90% more lignin content compared to bleached NCC (NCC-B). Nanocelluloses were incorporated within polypropylene (PP) as the matrix, together with kenaf core as a main reinforcement and maleic anhydride grafted polypropylene (MAPP) as a coupling agent via a melt mixing compounding process. The result showed that the thermal stability of the nanocomposites was generally affected by the presence of lignin in NCC-UB and sulfate group on the surface of NCC-B. The residual lignin in NCC-UB appeared to overcome the poor thermal stability of the composites that was caused by sulfation during the hydrolysis process. The lignin helped to promote the late degradation of the nanocomposites, with the melting temperature occurring at a relatively higher temperature of 219.1 °C for PP/NCC-UB, compared to 185.9 °C for PP/NCC-B. Between the two types of nanocomposites, PP/NCC-B had notably lower thermo-mechanical properties, which can be attributed to the poor bonding and dispersion properties of the NCC-B in the nanocomposites blend. The PP/NCC-UB showed better thermal properties due to the effect of residual lignin, which acted as a compatibilizer between NCC-UB and polymer matrix, thus improved the bonding properties. The residual lignin in PP/NCC-UB helped to promote char formation and slowed down the burning process, thus increasing the flame resistance of the nanocomposites. Overall, the residual lignin on the surface of NCC-UB appeared to aid better stability on the thermal and flammability properties of the nanocomposites

Investigations on Composite Flexural Behaviour with Inclusion of CNT Enhanced Silica Aerogel in Epoxy Nanocomposites

Abstract. Growing of carbon nanotubes (CNT) on the surface of highly porous silica aerogel offers a means to tailor the mechanical properties between fiber and matrix interface of a composite. The growth of CNT on the silica aerogel surface was done using chemical vapour deposition (CVD) technique. In this study, the morphology of the produced CNT was investigated by Scanning Electron Microscope (SEM) for confirmation of CNT existence. The composite were then prepared by shear mixing technique. Flexural strength of the CNTSilAe/Epoxy nanocomposite were assessed as a function of CNT-SilAe concentration and dispersion in epoxy matrix. The flexural modulus and strength of epoxy composite increased significantly with inclusion of CNT-SilAe. The optimum loading of CNT-SilAe in epoxy composites was attained at 2 wt%, where the improvement in flexural strength and modulus were 8% and 11%, respectively

Effect of impregnation on hybrid mesoporous silica / kenaf reinforced epoxy composites in term of flexural, compressive and water absorption properties

In this work, mesoporous silica with designated amount was added in kenaf/epoxy composites to improve the mechanical properties of the composite and reduce the water uptake of fabricated composites. The composites were fabricated using hot press method (HP) and impregnation method (IMP). For HP specimens, silica was dispersed into epoxy resin using homogenizer before being applied to the kenaf mat and subsequently hot pressed. While for IMP specimens, the kenaf mat was placed inside the silica/epoxy solution under 600 mm Hg impregnation pressure before being hot pressed. The results for flexural properties revealed that IMP specimen with 40 vol% of kenaf fibre and 5 vol% of silica have the highest strength and modulus at 78.6 MPa and 5.11 GPa respectively. Same trend can be seen for compressive properties as the same specimen had the highest compressive strength and modulus at 69.3 MPa and 1.81 GPa respectively. Finally for water absorption properties, IMP specimens had a reduction in water uptake compared to its HP specimen counterparts with the same kenaf and silica content. IMP specimen with 60 vol% kenaf and 5 vol% silica had the lowest water uptake after 90 days of immersion in distilled water at 13.5% increase in weight

Properties of alumina with RHA-reinforced aluminum composite using different sintering profile

The purpose of this research is to study the effect of different sintering profiles on the properties of porous alumina ceramic composites. The mixtures of alumina, rice husk ash (RHA), aluminum, and sucrose binder solution were compacted and went through three different sintering profiles which involve two non-continuous procedures and one continuous procedure. In non-continuous, it involves two different profiles which are with and without pre-treated at 1000°C. To summarize, the three processing profiles used for this study were (S1) non-continuous (without 1000°C), (S2) non-continuous (with 1000°C), and (S3) continuous (with 1000°C). Results from this study show that S2 gives better properties than S1 and S3. From microstructure evaluation, S2 provided lower total porosity. Mechanical properties also revealed that the sintering linear shrinkage measured for S2 has the highest value (2.38%) which results in the highest density (1.43 g/cm3), lowest total porosity (48.05%), and the highest tensile strength (9.26 MPa)

Significant effect of rice husk and sugarcane bagasse pore formers on the microstructure and mechanical properties of porous Al2O3/Ni composites

Temitope, Dele-Afolabi/0000-0003-0187-9208; Sobri, Shafreeza/0000-0002-5675-2186; Mazlan, Norkhairunnisa/0000-0003-0144-8360WOS: 000427511200038Porous alumina systems are suitable for application in wide-ranging industrial processes that require extreme service conditions such as high temperatures and corrosive mediums due to their remarkable thermal and chemical stability. Given the inherent brittleness of ceramics and their high sensitivity to thermo-mechanical loading, large-scale production of porous alumina components is constrained. In this study, the reinforcement of porous alumina ceramics with nickel (Ni) particles has been reported. Plain and Ni-reinforced porous alumina ceramics were developed through the powder metallurgy method with agro-waste materials from rice husk (RH) and sugarcane bagasse (SCB) as the pore-forming agents (PFAs). Experimental results showed that the formation of a stable Ni3Al2SiO8 spinelloid phase in the RH-graded composites actuated the emergence of a relatively refined microstructure while on the other hand, microstructural defects such as dislocated grains and localized voids were observed for the SCB-graded counterparts due to the presence of poorly crystallized NiAl2O4 spinel phase. Generally from the mechanical strength characterization, an inverse relationship was established between the mechanical properties and Ni reinforcement which agrees well with the Griffith's model. Moreover, the strengthening effect of the Ni3Al2SiO8 spinelloid phase was well marked in the RH-graded composites as maximum hardness, tensile and compressive strengths of 167.3HV, 12.6 MPa and 55.3 MPa respectively were achieved for the composite reinforced with 2 wt% Ni. (c) 2018 Elsevier B.V. All rights reserved.Research Management Center of Universiti Putra Malaysia [GP-IPS/2016/9486500]; Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey [2016/44]The authors are thankful to the Research Management Center of Universiti Putra Malaysia for providing financial support (GP-IPS/2016/9486500) to carry out this research study. The authors also acknowledge the Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey for the ongoing partnership, financial support (project number of 2016/44) and fruitful feedback